Unit 2 (matched pairs and 2 sample tests)

Question 1

What is a matched pairs test

Answer 1

where each subject (or carefully pared subjects) gets both treatments. Ex pain pills A and B given to the same person at different times. We care a bout the differences between the scores (A-B)

Question 2

Matched pairs notation

Answer 2

Standard deviation = Sd, mean of differences = Xbar d, mu = ud

Question 3

Hypothesis testing for matched pairs

Answer 3

H0 will always be ud = 0, Ha can be ud > 0, ud < 0, ud doesnt = 0. We use t for matched pairs

Question 4

matched pairs formulas

Answer 4

swap z with t, sigma with Sd, Xbar with Xbard, and mu =0. works for both conf interval and test stat.

Question 5

how to get Xbard

Answer 5

add up all the differences from each coloum, then divide by the number of coloums

Question 6

tails in matched pairs

Answer 6

be careful how you set up the question, something that sounds like an upper could be a lower. For example if youre testing to see if IQ improves, then even though that sounds like upper, it will be a lower tail because (normal - BIGGER IQ) will result in a NEGATIVE NUMBER

Question 7

How to tell when it’s a Two sample test

Answer 7

When it’s a two sample test, we will have 2 n’s (may be the same size), two Sd’s and two Xbarsd’s

Question 8

Confidence interval for a two sample test

Answer 8

(Xbar1 - Xbar2) +/- t* (SE)

Question 9

Hypothesis testing for two sample test

Answer 9

H0: u1 = u2 vs HA u1>u2 OR u1 < u2 OR u1 doesnt = u2

Question 10

variance

Answer 10

is the standard deviation SQUARED

Question 11

When to use pooled vs non-pooled

Answer 11

if Bigger s / little s <2 use the POOLED METOD